中国农业科学 ›› 2019, Vol. 52 ›› Issue (17): 2972-2982.doi: 10.3864/j.issn.0578-1752.2019.17.006

• 植物保护 • 上一篇    下一篇

吡咯伯克霍尔德菌WY6-5产二甲基二硫对储藏期花生黄曲霉及毒素的抑制作用

宫安东(),董飞燕,吴楠楠,孔宪巍,赵倩,闫建丽,Cheelo DIMUNA   

  1. 信阳师范学院生命科学学院/河南省茶树生物学重点实验室,河南信阳 464000
  • 收稿日期:2019-04-18 接受日期:2019-05-13 出版日期:2019-09-01 发布日期:2019-09-10
  • 通讯作者: 宫安东
  • 作者简介:宫安东
  • 基金资助:
    国家自然科学基金(31701740);河南省科技攻关项目(172102110260);河南省科技攻关项目(182102110018);河南省科学技术研究重点项目(16A180036)

Inhibitory Effect of Dimethyl Disulfide from Burkholderia pyrrocinia WY6-5 on Aspergillus flavus and Aflatoxins in Peanuts During Storage Period

GONG AnDong(),DONG FeiYan,WU NanNan,KONG XianWei,ZHAO Qian,YAN JianLi,Cheelo DIMUNA   

  1. College of Life Science, Xinyang Normal University/Henan Key Laboratory of Tea Plant Biology, Xinyang 464000, Henan
  • Received:2019-04-18 Accepted:2019-05-13 Online:2019-09-01 Published:2019-09-10
  • Contact: AnDong GONG

摘要:

【目的】验证吡咯伯克霍尔德菌(Burkholderia pyrrocinia)WY6-5的抑菌作用,评价其对储藏期花生黄曲霉(Aspergillus flavus)及毒素的防治效果,分析抑菌作用机制,鉴定活性物质,并检测其最低抑菌浓度,为储藏期真菌病害及毒素的防控提供新材料。【方法】采用非接触培养皿对扣培养法,检测菌株WY6-5对黄曲霉的抑制效果,添加活性炭,验证挥发性物质的抑菌作用;密闭储藏环境,检测WY6-5产二甲基二硫对花生黄曲霉及毒素的抑制效果;收集处理后的花生籽粒,锇酸固定,并进行扫描电镜观察,检测黄曲霉细胞显微结构变化,通过透射电镜观察,检测黄曲霉细胞内部结构的显微差异;购买活性物质标准品,梯度稀释,与黄曲霉菌丝和孢子对扣培养,分析最低抑菌浓度。【结果】吡咯伯克霍尔德菌WY6-5分离自茶园根际土壤,可产生挥发性物质二甲基二硫,并高效抑制黄曲霉的生长,抑菌率达95%以上;同时,在高水活度(aw)条件下,WY6-5还可抑制储藏期花生黄曲霉和毒素污染;两种水活度下,对照组中发病率高达100%,黄曲霉毒素总含量分别为399.32 μg?kg -1(aw 0.859)和3 143.19 μg?kg -1(aw 0.923);WY6-5添加组,花生黄曲霉发病率降为2%(aw 0.859)与21%(aw 0.923),毒素含量降为4.86 μg?kg -1(aw 0.859)和121.37 μg?kg -1(aw 0.923),与对照组相比,对毒素的抑制率达98.78%和96.14%。扫描电镜观察显示,WY6-5产生的挥发性气体能抑制黄曲霉孢子的萌发,透射电镜显示,黄曲霉细胞结构未呈现明显损伤。挥发性物质二甲基二硫抑菌作用明显,对黄曲霉菌丝生长的最低抑菌浓度为100 μL?L -1(物质体积/培养体积),对孢子萌发的最低抑菌浓度为50 μL?L -1(物质体积/培养体积)。【结论】吡咯伯克霍尔德菌WY6-5可产生高效抑菌挥发物二甲基二硫,在低浓度下即可完全抑制黄曲霉菌丝生长和孢子萌发,并能抑制储藏期花生黄曲霉的侵染和黄曲霉毒素的产生,为储藏期真菌病害及毒素的防控提供了新型生物材料。

关键词: 吡咯伯克霍尔德菌, 黄曲霉, 黄曲霉毒素, 二甲基二硫, 抑菌, 储藏期

Abstract:

【Objective】The objective of this study is to verify the antifungal effect of Burkholderia pyrrocinia WY6-5, evaluate its control efficacy against Aspergillus flavus and aflatoxins in peanuts during storage period, analyze the inhibitory mechanism, identify antifungal volatiles and detect the minimal inhibitory concentration to A. flavus, so as to provide novel strategies for the prevention and control of fungal diseases and mycotoxin during storage period.【Method】Face-to-face dual cultural test was conducted to analyze the antifungal activity of volatiles from WY6-5. Active charcoal as volatile adsorbent was added into the tests to verify the antifungal activity of volatiles. Dimethyl disulfide (DMDS) emitted form strain WY6-5 was challenged with peanut kernels inoculated with A. flavus conidia in sealed airspace without physical contact. A. flavus cells on peanut coat were collected, fixed in osmic acid, and analyzed through scanning electron microscope (SEM). Transmission electron microscope (TEM) was used to test the inner structure of A. flavus cell affected by volatiles from WY6-5. The commercial DMDS was purchased, serially diluted, and co-cultured with A. flavus conidia and mycelia to detect the minimal inhibitory concentration, respectively.【Result】B. pyrrocinia WY6-5 isolated from rhizosphere soil of tea plants could produce volatile DMDS, prevent the growth of A. flavus mycelia, the inhibition rate was over 95%. Additionally, under the condition of high water activity (aw), WY6-5 could also inhibit the A. flavus infection and aflatoxins production in peanuts during storage period. In peanuts of control treatment, the disease incidence was 100%, and the total concentration of aflatoxins was 399.32 μg?kg -1 (aw 0.859) and 3 143.19 μg?kg -1 (aw 0.923), respectively. When WY6-5 was added in the treatment, the disease incidence decreased to 2% (aw 0.859) and 21% (aw 0.923), respectively. The concentration of aflatoxins decreased to 4.86 μg?kg -1 (aw 0.859) and 121.37 μg?kg -1 (aw 0.923), respectively. The inhibition rate of WY6-5 against aflatoxins contamination was 98.78% and 96.14% compared to the control treatment. SEM analysis proved that DMDS from WY6-5 inhibited the germination of A. flavus conidia. TEM analysis further proved that the inner cell structures of A. flavus conidia were not severely damaged by volatiles. Volatile DMDS showed great antifungal activity. The minimal inhibitory concentration against mycelia growth was 100 μL?L -1(compound volume/airspace volume). The minimal inhibitory concentration against conidia germination was 50 μL?L -1(compound volume/airspace volume). 【Conclusion】 B. pyrrocinia WY6-5 can produce valid antifungal volatile DMDS, which can completely inhibit the mycelia growth and conidia germination of A. flavus at low concentration, and greatly prevent the development of A. flavus disease and aflatoxins contamination in peanuts during storage period. WY6-5 and the produced DMDS provide novel bio-active agents for fungal diseases control and mycotoxins during storage period.

Key words: Burkholderia pyrrocinia, Aspergillus flavus, aflatoxin, dimethyl disulfide, antifungal, storage period